There is known a projector apparatus that collects illumination light from a light source to pass through a color wheel, irradiates the illumination light to a digital mirror device (DMD) that is a light modulation element to generate image light, and projects image light onto a screen or the like by a projection lens. In this case, illumination light emitted from the light source needs to be efficiently incident on the DMD via the color wheel.
In general, the illumination light emitted from the light source has a circular shape, and a light guide (rod lens) having a quadrangular prism shape is disposed behind the light source in order to match the illumination light to a rectangular shape of the DMD. However, among the illumination light emitted from the light source, there is light that does not enter the light guide, and in some cases, the light become unnecessary light and may adversely affect an image to be projected. In this regard, a configuration has been proposed in which a light-shielding plate for shielding unnecessary light is provided in the vicinity of an incidence plane or an emission plane of the light guide.
For example, Patent Document 1 proposes a configuration in which unnecessary light (harmful light) is suppressed by disposing a light-shielding plate (mask plate) having a rhombic opening in the vicinity of the emission plane of a light guide (rod integrator).